Over the years many different devices and methods have been used in loading cargo into the holds of deep water vessels and other haulage vehicles. Conveyor belts and pipes are used for particulate and fluid matter. Loads consisting of larger discrete objects are often handled by means of large portable containers. Food products such as rice are usually bagged and loaded in pallet sized stacks. Whatever arrangement is utilized for delivering the cargo from dockside or deckside through the cargo hatch to within the hold, the problem remains of finally dispensing the delivered cargo into their assigned locations in the wings of the hold. Typically, the crane utilized for delivering the cargo to a central location beneath the hatch is unable or unsuitable for appropriate removal of the cargo from the hatch area into the wing areas.
Typically, a large proportion of cargo space within a deep water vessel is located in the wing areas. Commonly, stevedores in the cargo hold must manually remove the cargo units from the delivery location and utilize mobile equipment for transporting the removed units to a remote location under the wing. With the limited load capacities of the mobile carriers such as fork lifts, frequent trips are required to complete any sizeable loading. Moreover, fork lifts are unsuitable for handling bag type cargo. Furthermore, they are characterized by limited stacking height capabilities frequently requiring manual labor to fill the remaining volume. Alternatively, the otherwise available cargo volume goes unused. In the process of stacking the cargo units in their assigned locations in the hold, the cargo units are usually handled individually or remain on a space-consuming pallet. Such manual handling has been recognized as time consuming and labor intensive amounting to a significant cost factor in the shipping expense of the goods that are ultimately passed on to the end user of the products which the cargo represents.
There has therefore been a long felt need to improve the disposition of delivered cargo from the delivery site location in the ship's hold to the final location within the wings of the hold selected for transport. Portable cargo loading equipment for fulfilling that purpose is disclosed in my co-pending application Ser. No. 830,235 filed Feb. 14, 1986, now abandoned. While functioning well for the intended purpose the equipment disclosed therein is characterized by a limited loading capacity on the order of about 2-3 metric tons per loading cycle depending on the size of the equipment selected. It has recently been recognized that much higher loading capacities on the order of ten metric tons per loading cycle and above would be highly cost effective and therefore desirable for many of the larger ocean going ships currently utilized. However, not only must such apparatus be characterized by the higher loading capacities, but it must be portable for hold placement and retrieval. Furthermore, it should preferably be self sufficient for both cargo placement and incremental self displacement for loading successive sites after loading of a selected site has been completed. Despite recognition of the problem, apparatus suitable for the larger capacities in satisfaction of the above has previously been unknown.